IDENTIFICATION OF INDUSTRIAL HAZARDS WITH RISK ASSESSMENT TECHNIQUE
There are many risk assessment technique
available in the industry which can be used to identify industrial hazards.
Below outlined the various techniques that can be used to identify hazards and
provide a brief overview of their advantages and disadvantages.
It should always be remembered that any
system or operation comprises:
people, procedures, equipment and an environment of operation
All these elements must be considered during
hazards identification.
Risk
Assessment Technique for Identification of Industrial Hazards
What-if analysis
Hazard and Operability Study (HAZOP)
Fault Tree Analysis
Event Tree Analysis
Failure Mode and Effects Analysis
Job Safety Analysis
In this post, only the following techniques
will be explained
HAZARD
AND OPERABILITY STUDY (HAZOP)
HAZOP is a systematic and structured approach
using parameter and deviation guidewords. The technique relies on a very
detailed system description being available for study and usually involves breaking
down the system into well defined subsystems and functional or process flows
between subsystems. Each element of the system is then subjected to discussion
within a multidisciplinary group of experts against the various combinations of
the guidewords and deviations.
The group discussion is facilitated by a
Chairman and the results of the discussion recorded by a Secretary together
including any hazards identified when a particular guideword and deviation
combination is discussed. Where a particular guideword and deviation
combination does not produce any hazards, or is not though t credible, this
should also be recorded to demonstrate completeness.
The guidewords and deviations must be
prepared in advance by the HAZOP Chairman and may need to be tailored to the
system or operation being studied.
In
an aviation context, typical guidewords might include:
Detection
Co-ordination
Notification
Transmission
Clearance
Authorisation
Selection
Transcription
Supervision
Typical
deviations might include:
Too soon / early
Too late
Too much
Too little
Too high
Too low
Missing
Twice / repeated
Out of sequence
Advantages
of Hazard and Operability Study
Systematic and rigorous.
Involves interaction of views from
multidisciplinary experts.
Can be applied to a wide range of types of
system.
Creates a detailed and auditable record of
the hazards identification process.
Disadvantages
of Hazard and Operability Study
Requires a considerable amount of
preparation.
Can rely heavily on the skills of the HAZOP Chairman
Can be time consuming and therefore
expensive.
Can inhibit imaginative thinking and so
certain kinds of hazards.
FAILURE
MODE AND EFFECT ANALYSIS.
FMEA is a ‘bottom up’ technique that is used
to consider ways in which the basic components of a system can fail to perform
their design intent. This could either be at an equipment level or at a functional
level. The technique relies on a detailed system description and considers the
ways in which each sub-component of the system could fail to meet its design
intent and what the consequences would be on the overall system. For each
sub-component of a system an FMEA considers:
All the potential ways that the component
could fail.
The effects that each of these failures would
have on the system behaviour.
The possible causes of the various failure
modes.
How the failures might be mitigated within
the system or its environment.
Behaviours at the system level arising from
the sub-component failures which have a safety consequence are thus identified
as hazards. The system level at which the analysis is applied can vary and is
determined by the level of detail of the system description used to support the
analysis. Depending on the nature and complexity of the system, the analysis
could be undertaken by an individual system expert or by a team of system
experts acting in group session.
Advantages
of FMEA
Systematic and rigorous.
Creates a detailed and auditable record of
the hazards identification process.
Can be applied to a wide range of types of
system.
Disadvantages
of FMEA
Only really considers hazards arising from
single point failure modes rather than combinations of failures.
Relies on people with detailed system
knowledge.
Can be time consuming and expensive
WHAT IF
What
If is developed as a simpler and more efficient alternative technique to HAZOP
Like HAZOP, What If involves a multidisciplinary team of experts under the
facilitation of a Chairman. It is a facilitated brainstorming group activity
but is typically carried out on a higher level system description , having
fewer sub elements, than for HAZOP and with a reduced set of prompts.
Ahead
of the group session the Chairman prepares a suitable list of prompts such as:
What
if...?
Could
someone...?
Has
anyone ever...?
The
Chairman uses the prompts to initiate discussion within the group.
Advantages of What If
Creates
a detailed and auditable record of the hazards identification process.
Is
less time consuming than other systematic techniques such as HAZOP.
Disadvantages of What If
Careful
thought is required in preparation for the application of the technique.
Relies
heavily on the expertise and experience of the team members.
Relies
heavily on the skills of the Chairman
